Electric discharge tube



' Oct. 8, 194( e. RABUTEAU 2,217,418

ELECTRIC DISCHARGE TUBQE Filed Nov. 11, 1936 Fig.4 Fig. 1.

ll// I m VE NTOR GUY RABUTEAU ATTOR HEY Patented Oct. 8, 1940 2,217,418

UNITED STATES PATENT OFFICE ELECTRIC DISCHARGE TUBE Guy Rabuteau, Paris, France, assignor to International Standard Electric Corporation, New York, N. Y.

Application November 11, 1936, Serial No. 110,256 In France December 12, 1935 12 Claims. (01 25027.5)

The present invention relates to" improvements Fig. is a sectional view taken along section 1 in means of support for electrodes of vacuum line 5-5 of Fig. 4. tubes or the like, Fig. 1 shows an anode l on which is fused at 3 The invention particularly relates to means for a sheath of vitreous material 2. Inside the en- 5 supporting electrodes the relative position of velope formed by anode l and sheath 2 are pro- 5 which must be fixed to within close limits and vided (1) a filament 4 with its current leads 5 has for an object to provide a simple and imand 6 sealed in the vitreous sheath 2 at a filaproved form of mounting for such electrodes. ment foot I; (2) a grid 8 placed inside the anode In accordance with one feature of the invenl around the filament 4 and supported by three tion, one at least of the electrodes of a vacuum leads 9, one of which is shown in Fig. 1. These 10: tube or the like forms a unitary structure with leads are interconnected by rings [0 and H. The a member adapted to be mounted by screwing, grid wire I2 is fixed on the grid rods 9 in the usual interlocking, or otherwise on an electrode supway, by means of a lacing 13, for example. port which preferably also forms a current con- The whole of the grid is carried by a tubular ductor and the position of which may be strictly lec ro e s pp t I4 fix in h i e W l of the 15 fixed during manufacture. Th electrode supsheath 2. The electrode support I4 is itself support may for example be maintained rigidly in ported by a metal member or bushing l5 fused position by a tool engaged in the screwing or at IE to the sheath 2. interlocking device provided in said support while e grid SUDD Q s 9 are fixed t0 the it is being fixed permanently to the tube; prefelectrode supp t M by means f a plug mem- 20 erably the axis of the electrode support forms her I! which is screwed at I8 to the support 14. an angle, for example an angle of 90 with the The whole grid structure constituted by the. axis of the corresponding electrode. member H, the rods 9, the rings 10 and H, and

The arrangement is particularly applicable in the grid wire I! has such dimensions that it can the case of tubes with coaxial electrodes. It is pass through the h in the pp Thus 5 moreover especially useful in tubes for short or the g y be Set in Place and n fixed by ultra-short waves where a small inter-electrode s w e member 11 mm the pp capacity is desired because the electrode support shown at l8 in Fi may be used as a current lead as already men- A locking screw l9 ay be screwed at 20 or 2| tioned and the axis of this current lead may be t t upp t M, Fig. 2, in order to lock the 30 different from that of the vacuum tube. ember ll and to prevent it from becomin 11 An electrode may according to the invention screwed under the influence of vibrations or durbe provided with one or several supports and g the anufacture of the tube. v where several supports are employed they may The support I4 is bored out along its axisat 22 be arranged for example as arms radiating round and laterally at 23, 23 in order to reduce its 35 the axis of the tube; the axis of one or more of Weight and to permit evacuation of air inside the these arms may be inclined with respect to the cavity 22. The support 4 s joined to the mem axis of the tube and the arms may be placed her l5 and to adiso or block 25, at 24 the three on one side or on either side of the electrode. members 5, I4 and I5 being interconnected by 40 The supports may be resilient or may be otherthe brazing 26. The end of the support l4 in- 40 wise arranged to prevent undue stress upon the side the joint is arrange s that a joint bewalls of the tube. tween the copper members l5 and 25 is directly The above and other features of the invenformed by means of the brazing 26, the end of tion will be better understood from the following the support l4 being recessed y 1 for ex- 5 description of an embodiment illustrated in the ample, with respect to the ends of the members v attached drawing in which: l5 and 25 as shown at 250..

Fig. 1 represents in elevation and in section It may be noted that in the embodiment shown a vacuum tube employing features of the inin Figs. 1-3, the rod l4 serves at the same time vention; p as a grid supporting member and as a leading-in Fig. 2 represents a view of the electrode supconductor for the rid- 5o p rting member; The fixing of the grid structure by means of- Fig. 3 represents a sectional view of the same the member I! screwing at I8 into the support member, I4 maybe-replaced by any other method of fix- Fig. 4 is an enlarged sectional view of the left ing, such as a bayonet joint, in which one or hand portion of the structure of Fig. 1; and more fingers are engaged in ramps provided for 55 this purpose in the support 14. Such alternative couplings may be provided with looking systems such as that represented by the screw 19 in Fig. 1, or by any other suitable locking device.

The supporting arrangement shown in Fig. 1 may be applied to several concentric or other grids or electrodes arranged to pass during mounting through the central hole 21 of the support 14.

The support l4 represented in Fig. 2, may instead of being in a single piece be composed of two pieces, the cylindrical portion being screwed or fixed by other means such as soldering or locking in the ring portion bearing the thread 18.

One of the advantages of the arrangement of Fig. 1 is that it facilitates the centering of the electrodes of the tube in particular the centering of the grid to the other electrodes; the placing of the support l4 in the sheath 2 of the anode I may be effected by means of a tool screwing in the thread 18, which tool is centered in such a way that the axis of the thread I8 exactly coincides with the axis of the anode I during the fixing the member M for example by soldering at 26 as shown in Fig. 1. The tool is subsequently removed from the tube and the grid is set in place by passing it through the hole 21 and screwing the member I! in the member I 4 in the threads l8.

The grid having been made coaxial with the axis of the threads [8 of the member I! becomes coaxial with the anode I. In order to facilitate the centering of the grid a hole I may be provided in the anode l this hole being subsequently blocked up in a suitable manner.

When several arms are provided for the grid support, these arms need not necessarily be rectilinear and may be curved so that the thread I8 is in a difierent plane from that of the arms of the support M.

The invention is not limited to the embodiment described, for example, radiating arms serving as supports and preferably as currentleads to the electrodes may be arranged in different planes, for example, in parallel planes. In the same way at least one of the supporting members of an electrode may be composed of telescopic tubes mounted with suflicient friction to permit extension without looseness or other harmful efiects. Finally the device described may be applied not only to power tubes of the type with one or two bulbs but also to entirely metal tubes and to low power tubes such as receiving tubes.

What is claimed is:

1. An electrical discharge tube comprising in combination an envelope, an apertured supporting member fixed therein, an electrode structure, and coupling means including a plug portion fixedly positioned within the aperture of said supporting member for fixing said electrode structure to said supporting member.

2. An electric discharge tube comprising in combination an envelope, an aperture supporting member fixed therein, an electrode structure and a coupling member screw threaded in said aperture and a rod fixing said electrode structure to said coupling member.

3. An electric discharge tube comprising in combination a cylindrical envelope, a radial arm fixed therein, an axial socket in the radial arm, an axial electrode structure and a member attached thereto engaging said axial socket.

4. An electric discharge tube comprising in combination an envelope, a ring mounted intermediate the sides of the envelope, a bushing inserted in said ring and an electrode structure attached to said bushing and supported solely thereby.

5. Method of assembling an electrode structure and a supporting arm having an opening therein within a vacuum tube consisting in fixing the supporting arm to the tube in predetermined relation thereto, passing said electrode structure through said opening in the supporting arm and securing said electrode structure at one end thereof to the supporting arm.

6. An electric discharge tube comprising in combination an envelope, a plurality of electrodes therein, an electrode support fixed in predetermined relation to one electrode, an intermediate supporting member for another electrode and a. plug and socket coupling between said electrode support and said intermediate supporting member.

7. An electric discharge tube comprising in combination an envelope, a plurality of coaxial electrodes, a supporting arm fixed to the envelope at an angle to the axis of the electrodes, an intermediate supporting member for an electrode and telescoping coupling means between said supporting arm and said intermediate supporting member retaining said intermediate supporting member parallel to the axis of the electrodes.

8. An electric discharge tube comprising in combination an envelope, a plurality of coaxial electrodes, a supporting arm fixed to the envelope at an angle to the axis of the electrodes, an axial aperture in said supporting arm and an axially arranged intermediate supporting member forming a unitary structure with one of said electrodes and having one end inserted and fixed in said axial aperture.

9. An electric discharge tube comprising in combination a cylindrical envelope, a plurality of electrodes coaxially disposed about the axis of said envelope, at least one radial supporting arm fixed in the envelope, a plurality of intermediate supporting members parallel to the axis and forming a unitary structure with one of said electrodes and preformed coupling means between said radial supporting arm and said intermediate supporting members.

10. A vacuum tube comprising in combination a cylindrical anode, a vitreous chamber forming with the anode a sealed envelope, a cylindrical grid structure within said anode and coaxial therewith, a grid supporting arm fixed in predetermined position in the vitreous chamber, an aperture in said grid-supporting arm and means inserted in said aperture and carrying said grid structure.

11. A vacuum tube according to claim 1 said electrode structure having a diameter smaller than the aperture diameter so that it may be passed through said aperture.

12. In combination in a vacuum tube, a glass envelope, a metal support having a tubular stem extending through said envelope and closed at its outer end by a disc, a member encircling said stem and having a flange fused to the said envelope around the said stem and metallic means joining said disc to said member.

GUY RABUTEAU. 

